This application claims benefit of provisional application No. 60/628,387, filed Nov. 15, 2004.
The present invention relates to the general field of frame apparatus of the kind constructed to be mounted on the trunk of a tree for use by arborists for handling loads in arbor rigging procedures.
The present invention relates particularly to a flip-out function converter apparatus that is attachable to a tree-mountable frame apparatus such that it can be placed by a field operator in either a stowed positional mode or in an operational mode. In the stowed mode, the frame apparatus can function in its original design mode without interference from the converter apparatus. When the function converter is placed into a position for its operational mode, the frame apparatus is converted to a different functional and operational mode. In its operational mode, the function converter provides a suitable contact interface between the frame apparatus and a tree trunk and also provides appropriate structural elements to transfer high operational load forces from the frame apparatus to a tree trunk. Thus, the function converter is utilized to increase the number of optimal functions of a single frame apparatus and thereby to increase the applicability of the frame apparatus for a wider range of arbor rigging procedures with high effectiveness and with improved efficiency in the use of materials and operator labor.
Arborists frequently use a variety of frame apparatus attachable to the trunk of a tree for lifting, lowering, or constraining heavy loads in arbor rigging procedures. The two most common general functions of such devices are 1) to enable arborists to safely and efficiently trim, top and cable (i.e., maintain) live trees and 2) to safely and efficiently remove dead or live trees. The present invention will enable an arborist to perform both of these general rigging functions effectively and efficiently with a single frame apparatus and, thereby, reduce the overall operational costs of such arbor rigging procedures.
Existing tree-mountable frame apparatus are commonly found to have functionally unused recessed regions or cavities on the tree-facing side of the frame within the outer contours of tree-contact points of the frame apparatus. Although some of these regions are relatively small in volume, they provide the potential for the attachment and non-interference stowage of additional functional apparatus. Such recessed regions in frame apparatus are utilized in the applications of the present invention to extend the functional range of either a frame apparatus with spikes or a frame apparatus with pads.
For removal of either a live or dead tree, a frame apparatus with spikes (or pins) is commonly attached to the trunk of the tree for frame stability. In this use, any frame damage to the bark or cambium layer of the tree is not important. However, for the trimming, cabling and topping of live trees, damage to tree bark and cambium layer by spikes on a frame apparatus can result in stunted growth of the tree, in scaring of the tree bark, or, in severe cases, in killing the tree, particularly if it is a relatively small tree and doesn't receive adequate care after the damage. Damage to live trees from frame apparatus with spikes results not only from vertical load forces on a frame apparatus during rigging procedures but also from penetration of the bark and cambium in combination with the circumferential motion of the frame apparatus around a tree trunk produced by tightening of the mounting strap as the frame apparatus is mounted onto a tree trunk. Also, a frame apparatus is occasionally mounted on a nearby live tree as part of the arborist rigging procedure for removing a dead or live tree and sometimes for trimming, cabling or topping a nearby live tree. The shock loading of tree-mounted frame apparatus during arbor rigging procedures to remove tree limbs or stemwood commonly produce load forces on the frame apparatus that can exceed 2000 pounds.
U.S. Pat. No. 4,239,188 issued Dec. 16, 1980 to Hobbs and entitled “Tree Handling Device” and U.S. Pat. No. 5,484,253 issued Jan. 16, 1996 to Johnson and entitled “Conformed Frame Apparatus for Handling Loads Involved in Arbor Rigging Procedures” disclose frame apparatus which use spikes (pins) that are inserted into a tree trunk to improve stability of the frame during its use in arbor rigging procedures. U.S. Pat. No. 4,314,693 issued Feb. 9, 1982 to Hobbs and entitled “Device for Arborist Contractors” in reference to Hobbs' U.S. Pat. No. 4,239,188 states that: “Both forms of the invention described in the co-pending application damaged the tree to some extent either because a spike was driven into the tree or a notch was actually formed in the tree with a chain saw. These patents are incorporated by reference in this application.
Many arborists, who own or have access only to a frame apparatus with spikes for arbor rigging procedures on live trees, commonly use a separate elastomeric pad that is placed between the frame apparatus with spikes and a live tree on which it is being mounted to reduce spike damage to the tree bark and cambium. Each time the spiked frame apparatus is substantially repositioned on the tree, as commonly occurs during the rigging procedures, the pad must also be moved. This process increases the time (and thus the cost) required to complete the rigging procedures, as well as incurring costs for the elastomeric pads when they are damaged or lost. Such manually inserted pads, already cut to an appropriate size for use with a spiked frame apparatus, are now commercially available.
Attachment of an embodiment of the function converter apparatus of the present invention to a frame apparatus with spikes will convert the frame apparatus such that it can be used effectively and economically in arbor rigging procedures for trimming, cabling, and topping of live trees without producing spike damage to the tree bark and cambium. For this application the function converter apparatus in its operational mode not only shields the spikes from contact with tree bark and cambium, it also provides a suitable interface with the tree trunk and has the necessary structural elements to transfer the often high operational loads from the frame apparatus to the tree trunk. These operational features of the function converter distinguish this invention from a variety of flip-down devices that do not modify the operational and functional characteristics of the devices to which they are attached. See, for example, the U.S. Pat. No. 6,439,595 issued Aug. 27, 2002 to Cheng, et al.
To reduce frame damage to bark and cambium of a live tree, an embodiment of the frame apparatus disclosed in U.S. Pat. No. 5,484,253 includes elastomeric pads for contact points with the tree trunk. However, these pads are contained within rather complex, and thus relatively expensive, receptacles that are permanently attached to the frame apparatus. The pads cannot be removed when the frame apparatus is used in the removal of live or dead trees because the pad receptacles would be damaged during the rigging procedures. The pads also receive high stress and strain in the process of lowering heavy loads that are common during tree removal rigging processes. This process shortens the useful life of the pads and adds to the overall cost of using the padded frame apparatus. The load ratings for frames with pads are typically lower than similar frames with spikes.
U.S. Pat. No. 5,971,363 issued Oct. 26, 1999 to Good and entitled “Tree Winch Mounting System” also discloses the use of multiple compressible pads on the tree facing side of a tree winch mounting system to increase the resistance of the mounting system to vertical motion and to reduce damage to the tree trunk during rigging procedures. This patent is incorporated in this application by reference.
With only the pads of a frame apparatus interfacing with a tree trunk, particularly with heavy shock loads often present during tree removals, tree-mounted frame apparatus sometimes slides up the tree trunk when load forces are high. An example of a vertical displacement on prior art frame apparatus may be seen in Sherrill Inc., Arborist Supply Catalog, 2002, 11th Edition, page 22. The extent of vertical motion is highly dependent on load force, tree trunk shapes, tree bark structure and compressibility, and on frame apparatus mounting strap tension.
An embodiment of a frame apparatus shown in the aforementioned U.S. Pat. No. 5,484,253 of Johnson includes a hinged swing-out spike device to increase frame apparatus stability during loading. However, in this embodiment the spike assemblies are attached to and stowed on outer end portions of the frame structure, and this positional constraint limits the functional adaptability and suitability of the spikes. In this embodiment, the principal spikes for the penetration of a tree trunk during the mounting of the frame apparatus onto a tree trunk are attached to the outer end portion of the lower frame structure and are rotated outward beyond that outer end by the field operators. In this operational mode, the spikes are in an approximate vertical configuration, i.e., notched out of a metal flap that generally defines a vertical plane. Thus, they provide only a limited restraining area for resistance to high vertical forces, and cannot bite as effectively into the tree trunk as can generally horizontal spikes. In this embodiment, a flip-out spike attached to the outer top of the frame apparatus (and horizontal pivot axis) is commonly not effective in penetrating the tree trunk due, in part, to the circumferential motion of the frame during the process of mounting of the frame apparatus onto the tree trunk. Also, penetration of the tree trunk by this spike when the load beam of the frame apparatus is loaded is often not fully effective due to the irregular or sloping shape of the tree trunk or due to the thick and rough physical characteristics of some tree bark.
The present invention, in an embodiment utilizing a flip-out function converter apparatus with spikes, readily accommodates the use of operationally horizontal spikes with large horizontal interaction areas. These areas can be comparable to those commonly used on the patented frame apparatus with spikes discussed above and fully adequate to provide vertical frame stability for the high loads commonly encountered in tree-removal rigging procedures. For this embodiment of the flip-out function converter apparatus with spikes, it can be placed by the field operator in a non-interference positional mode within recesses in the tree-facing side of the frame apparatus whenever rigging procedures on live trees require the use of the rigidly fixed compressible pads on the frame apparatus.
The performance of a single rigging frame apparatus, that is presently available and constructed to be mounted on the trunk of a tree for use by arborists, is generally not optimal for both the removal of trees and for the maintenance of live trees. With integration of the present invention with such apparatus, the overall performance for both applications can be fully suitable with a single frame apparatus.
It is an object of the invention to enable a field operator easily and quickly to place a flip-out function converter apparatus into a stowed position in a recessed region on the tree-facing side of a frame apparatus with spikes so the converter apparatus does not interfere with the use of the spikes when the frame apparatus is used in rigging procedures to remove dead or live trees.
It is also an object of this invention to provide small but effective embodiments of function converters which may be stowed in small recessed regions on the tree-facing side of a tree-mountable frame apparatus with spikes such that they do not interfere with the original design function of the frame apparatus but also enables the frame apparatus to be effectively used on live trees when the function converter is placed in an operational mode to prevent spike damage to the tree bark and cambium. In this embodiment, a field operator can also quickly and easily select for the operational mode either an elastomeric material or a hard surface material as the interface surface for contact with a tree trunk.
Additionally, when the function converter is in its operational positions, it is an object of this invention to transfer, with appropriate converter structural elements, significant portions of the often high operational load forces on the frame apparatus through the function converter apparatus to the tree on which the frame apparatus is mounted.
It is a further object of this invention to enable an embodiment of the flip-out function converter apparatus which contains spikes to convert a tree-mountable frame apparatus whose tree interface contact points are elastomeric pads, into a device fully suitable for rigging procedures to remove dead or live trees. Thus, the invention encompasses a frame with fixed spikes selectively coverable or shieldable by a pad to protect the tree, or vice versa, a frame with fixed pads to protect the tree, selectively shieldable by a hinged flip device with one or more spikes, preferably horizontal-plane spikes.
It is a further object of the invention to enable a field operator easily and quickly to flip a hinged function converter apparatus with spikes into a stowed position on the frame apparatus with pads such that the converter apparatus does not interfere with the use of the frame apparatus with pads in rigging procedures for live trees.
Moreover, an object of the invention is to reduce the hazards to field operators when handling a frame apparatus with spikes, by keeping the function converter apparatus in an operational position which shields the spikes from inadvertent contact with the operator.
It is another object of this invention to protect frame spikes from bending or becoming dull from inadvertent contact with hard surfaces when being handled in the field, transported, or placed into storage.
Finally, another object is to remove the need for handling an unattached, large elastomeric pad for protecting a live tree from spike damage when a field operator uses a tree-mounted frame apparatus with spikes.